A unique video disc system has been described by Clemens in U.S. Pat. No. 3,842,194. According to this system, disc replicas are fabricated having geometric variations in the bottom of a spiral groove in the disc surface which correspond to capacitance variations representative of video signals.
The disc masters are made by coating a flat aluminum disc with a lacquer or a bright copper layer. A continuous spiral groove about one micron deep having a pitch of about 2000 to 8000 grooves per inch (about 787 to 3150 grooves per cm) is then cut into the surface of the disc, preferably according to the method described by Nosker and Fox in U.S. Pat. No. 3,882,214. The disc master is then coated with an electron beam resist, the information desired recorded by means of a video-signal-modulated electron beam produced by a scanning electron microscope, and the resist developed to translate the information into a surface relief pattern in the bottom of the groove. This developed master is then replicated to form a stamping master from which a plurality of replicas can be made using conventional audio record techniques. The stamping master is made by first depositing a thin gold film on the developed resist layer and then electroplating a thicker layer of nickel. This electroformed replica, or stamping master, is separated at the resist/gold interface by peeling the stamping master from the resist surface.
When electron beam resists of olefin-SO.sub.2 copolymers, described in copending application of Kaplan and Davidson, Ser. No. 401,213 filed Sept. 27, 1973 are employed, the developed films are sensitive to the nickel electroplating step. The result is a lack of adhesion and a lifting of the resist during the electroplating, thereby distorting, or even destroying, the developed information pattern.